Source

== Rules for contributing to TortoiseHg ==
Note that these rules may change together with the code base as the project
evolves. Specifically, the compatibility rules in the default branch may be
different from those in the stable branch.
=== Library compatibility ===
Our code base assumes minimum versions of library components as listed below.
That is, our code must not depend on features or API's that were introduced
in any later versions of the respective components.
It may be ok though if some advanced user interface features are available only
if later versions of a library are found to be present at runtime, provided the
application is still reasonably usable with the base library versions listed
below.
PyQt: 4.6
=== Python version ===
TortoiseHg needs to run on Python 2.4, to stay consistent with Mercurial
itself.